1. Field of the Invention
This invention relates to a page display system, a method of displaying pages, and a recording medium containing a program for displaying pages, and particularly relates to a page display system, a method therefor, and a recording medium containing a program for indicating pages, utilizing after-images.
This application is based on Patent Application No. Hei.9-302896 filed in Japan, the content of which is incorporated herein by reference.
2. Background Art
Four million years have passed since the birth of human beings. The invention of paper brought a great progress in accumulation of information. The invention of the typography by Gutenberg in the fifteenth century has further produced remarkable progress in the transmission and accumulation of information. Until recent years, paper has been widely used as a recording medium due to its fine visibility. Paper is thin, supple, and elastic. These characteristics of paper enable reading of printed papers by handling papers and turning pages such that parcels of necessary information are extracted by identifying letters as a pattern from many pages in a bundle of papers within a short time.
Recently, as computerization advances with the progress of electronics, called the second industrial revolution, information is often displayed by display devices such as cathode-ray tubes and LCDs (Liquid Crystal Display). However, since such devices are self-luminous and inferior in resolution, letters or lines of letters as patterns displayed in such display devices are inferior in high speed and intuitive visibility than those on paper. This constitutes a basic reason for obstruction of the spread of electronic apparatuses for displaying lengthy documents such as, for example, electronic books, and obstruction of the arrival of the paperless age.
Japanese Patent Application, First Publication No. Sho 62-18595 discloses a display device which is capable of improving visibility by utilizing after-images. This device displays a sum of both multiplication products, one of which is a multiplication product of an output of a first frame buffer by an output from a display control circuit and another is a multiplication product of an output of a second frame buffer by a compliment of an output of a display control circuit.
The first problem of the hereinabove described conventional device is in that it is not possible for the device to control the timing of the displayed after-image at any time on request of a user. The problem is due to the fact that the time to display the after-image is not alterable, since an output from the display control circuit is constantly being generated.
The second problem is that the conventional device cannot perform processing of structured text. This is because the device is not provided with means to convert the structured text into picture images.
The third problem is that the device cannnot send or scroll pages in the opposite direction (that is, return to the previous images). This is because the device is not provided with a means to send pages in the opposite direction.
It is therefore the object of the present invention to provide a system which is capable of improving the visibility of letters or lines of letters as patterns by increasing an information content displayed at a time point by composing the after-image of the previous page on the presently displayed page as well as by increasing the total time for displaying one page.